Research On Flow Field And Material Movement In Shaft Furnace With AGD Pipes

The direct reduction gas-based shaft furnace is a gas-solid countercurrent short-flow steelmaking equipment,which uses reducing gases gradually reduce the pellets bed in the furnace.The product sponge iron can be used as an electric furnace for steelmaking.High-quality raw materials further produce high-quality steel.This process equipment can reduce the dependence of coke,and fit in the requirements of green production advocated by the state.This paper mainly investigates the improvement of reducing gas distribution by the installation of AGD pipes in the furnace and the effect of the installation of AGD pipes on the falling rate of the pellets layer to provides theoretical guidance and data support for Industrial production.This paper first calculates the minimum reducing gas demand and the minimum cooling gas demand,and then uses Fluent simulation to analyze the distribution of the reducing gas flow rate and pressure along its axial direction at different heights of the pellets bed in the furnace with different AGD pipes,and the radial distribution of the reducing gas flow rate and pressure in each shaft furnace was compared and analyzed when the shaft furnace height was 5m,6m,and 7m.This shows that the AGD pipes can increase the pressure in the furnace and improve the phenomenon of uneven distribution of reducing gas in the middle of furnace,the use of double AGD pipes or cross-arranged AGD pipes in the shaft furnace has a more significant effect on improving the reducing gas distribution in the furnace.Secondly,based on the discrete element method,a kinematic model of the pellets bed in the shaft furnace was established.The tracer layer method was used to compare and analyze the movement pattern and radial velocity distribution of the material layer in the shaft furnace with AGD pipes.The degree of influence of the setting of different AGD pipes on the pellets descent speed shows that the downward velocity distribution of the upper layer of each shaft furnace is uniform,and the radial velocity distribution of the pellets layer near the pipes is uneven and the shape fluctuates greatly.Setting the AGD pipes can improve the radial distribution unevenness of the lower pellets layer in the furnace.The vertical cross AGD pipes have the least influence on the movement of the pellets layer,and the effects of setting the AGD pipes on the compression force of the pellets layer in the furnace are studied.Finally,based on the DEM method and the Relative Wear model,the wear and load distribution of the spiral blade were studied,and the effects of the pellets layer height,pellets size ratio,and blade rotation speed on its wear depth were investigated.The research shows that the wear depth of each blade of the spindle of spiral gradually decreases from blade 1 to blade 6,and the wear depth of blade 1,blade 2,and blade 3 is relatively large as a whole.The amount of wear indirectly reflects the wear state of the blade.As the height of the particles bed increases,the spiral speed increases,and the proportion of large particles increases,the wear depth of the blade will also increase.